Hi Anand,
I think we'd need more information on what you've tried. Assuming you have your UI configured to use the "dspace" theme (in your config.dev.yml) and are running the site in development mode (yarn start:dev), then you should see the site automatically rebuild & update anytime you make a small change to that "home-news.component.html". Sometimes it may take a few minutes for the rebuild to occur, but you should see that your console window (where you ran "yarn start:dev") will detect that you've saved changes to that file, and then say it is rebuilding. Once it completes, you should see the changes in your browser.
You also may want to ensure that your browser itself is not simply caching the old page. You can try a hard refresh (hold down "Ctrl" key and click reload in your browser window), or you could open up a new browser window in "Incognito Mode". Based on your browser settings, it's possible the browser is simply displaying the old page, even though it's been updated successfully.
Tim